Pamela - The fixes that have been updated for the most part have not been software maintained by Apple, but by the Open Source Community. So as vulnerabilites are being found, they are being patched. Apple is fixing these holes before they are being exploited. (That is assuming that the hacker can even access your machine).
Microsoft still has something around 39 publically known security flaws in Internet Explorer alone left wide open for exploitation.
I am not picking a fight...but Apple is allowed to update areas that MIGHT be vulnerable...3 updates is a joke compared to like 300 security updates on windows xp side...and to this point, there has been no nasty expensive viruses to plague the mac world that I have ever heard of...so I can handle 3 security updates from apple...I am glad to see at least they notice before it costs companies millons of dollars and major losses and headaches then have them go OOPS..better to catch it before hand in my humble opinion...
Well Pamela, you shouldn't need to feel nervous unless you have your computer wide open for the internet.
I doubt you have Remote Login, and FTP Access turned on all the time, which are the two weakest spots in Mac OS X for someone to gain access into the computer. I'm pretty sure that Apple for the most part is playing it as "better safe then sorry".
I know I have Remote Login and FTP Access enabled on my machines, but only within my network (you can't access it from the internet since my router's firewall doesn't permit anything through), so my machines have the doors available, but one still has to go through the door to access the machine.
The largest differences between Mac and Windows security updates is that Mac ones haven't been exploited. (At least none that I know of) While Windows ones may have been, and if not, there is an exploit later in order to try and access computers that aren't patched. (Which is many of them.)